a) Field of the Invention
The present invention relates to a container for an integrated circuit wafer. More particularly, the invention relates to a container that imparts excellent anti-oxidant properties to an integrated circuit wafer and lowers the generation of dust.
b) Description of the Prior Art
Containers presently used for the storage and transportation of wafers for integrated circuits (hereinafter abbreviated as IC-wafer) are prepared from resins such as polyethylene, polypropylene and rigid polyvinyl chloride. The IC-wafer is encased in a molded box and covered with a separately produced lid. Japanese Patent Publication No. KOKOKU Sho 61-46970(1986) discloses an encasing package consisting of a metal film into which an IC-wafer is placed, which is covered with a rigid plastic such as rigid polyvinyl chloride film.
Japanese Utility Model Laid-Open No. 112146/1987 describes an encasing box for an IC-wafer that is equipped with a ventilation device that provides a dust-proofing function.
These patents and the above model also disclosed storing an IC-wafer in an environment of inert gases such as nitrogen.
Surface oxidation of the wafer has been a serious problem with the use of the presently available containers. Oxygen penetrates through the conventional polyethylene containers and causes remarkable oxidation on the surface of the IC-wafer. Consequently, the oxidized surface requires further treatment such as chemical or abrasion treatment.
Friction between the IC-wafer and the resin during transportation produces abraded particulates and dust of the resin and results in problems such as adhesion of foreign particulates on the surface of the IC-wafer.